An integrated survey in Optical Networks: Concepts, Components and Problems Delivered by Erna Sri...
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Transcript of An integrated survey in Optical Networks: Concepts, Components and Problems Delivered by Erna Sri...
An integrated survey in Optical Networks: Concepts, Components and Problems
Delivered byErna Sri Sugesti, Ir., MSc.
1 May 2013
Ali Norouzi †, A.Halim Zaim ††, Berk Burak Ustundag, IJCSNS International Journal of Computer Science and Network Security, VOL.11 No.1, January 2011
1. INTRODUCTION
Point-to-point link apparatus: Overview
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Tx Rx
Optical Sources:• LED• LASER
Optical Detector:• p-i-n photodiode• Avalanche photodiode (APD)
Optical fiber
Transmission medium
Types:Single ModeStep Index MultimodeGraded Index Multimode
Characteristics:AttenuationDispersion
Characteristics:ResponsitivityQuantum EfficiencySensivity
Characteristics:Optical output powerWavelength Linewidth
splicesconnectors
Optical fiber system advantages:
• Wider bandwidth• Low transmission loss• Dielectric waveguide• Small size and weight
Main parts of optical fiber networks:
1. Optical technologies2. Components that provide routing and
grooming3. Restoration at wavelength level as well as
wavelength-based services
2. MATERIAL AND METHODS
2. 1 Optical network properties3 properties for next generation access networks:1. Point-to-point topologies2. Passive optical networks3. Optical wireless technologies
Fig. 2 Structure of a point-to-point WDM transmission system.
Fig. 1 Different technologies for fiber-to-the-home (FTTH).
Cont’: Optical wireless technology
Optical networks development goal: to move toward dynamic all-optical networks
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Tx RxFree space medium
2.2 Optical network components • Transmitter: DFB, DBR• Multiplexer and Demultiplexer• Fiber Properties: SM• Optical Amplifiers: SOA, EDFA, EDWA• Optical Switches: WRS• Receivers: p-i-n, APD
Fig. 9 Structure of a MEMS wavelength routing switch. Micromirrors are used to guide input beam to different outputs.
Fig. 8 The general structure of an optical switch
• TDM• WDM, CWDM, DWDM
2.3 Multiplexing techniques
2.4 Optical WDM Networks
• Network with optical fiber transmission links and architecture designed to exploit the unique features of fibers and WDM
2.5 Problems of Designing Wavelength RoutingGeneral problems:• Fiber (network) topology• Traffic requirements (traffic matrix)
2.6 Network design and fiber topology problems
• Light Topology Design (LTD)
• Routing and Wavelength Assignment (RWA)
• Wavelength continuity constraint
• Distinct wavelength constraint
2.7 Grooming the higher-layer traffic
• SDH (synchronous digital hierarchy)• SONET (synchronous optical network)
3. RESULTS & DISCUSSION
3.1 RWA Problems in Optical Networks
• Finding a path and a free wavelength for a source destination pair
3.2 Classifying RWA based on Routing
1. Static routing algorithms2. Adaptive routing algorithms3. Dynamic routing algorithms
3.2.1 Static routing algorithms
• Fixed Path Routing• Fixed Alternate Routing
3.2.2 Adaptive routing algorithms
• Adaptive Routing• Traditional Adaptive RWA• Physically Aware Adaptive RWA
3.2.3 Dynamic routing algorithms
Connection requests are initiated randomly.Steps:• Compute a number of candidate physical paths
for each source-destination edge node pair and arrange the min a path list.
• Order all wavelengths in a wavelength list.• Starting with the path and wavelength at the top
of the corresponding list, search for a feasible path and wavelength for the requested lightpath.
3.3 Classifying RWA based on Propagation
• Centralized architecture• Distributed architecture
3.4 Wavelength Assignment (WA) ProblemConstraints:• Distinct Channel Assignment (DCA)• Wavelength ContinuityWA-algorithm:• Random-fit• First-fit• Most-used
3.5 Physical Impairment
• Linear effects• Nonlinear effects
3.6 Linear Impairment
• Fiber attenuation• Components insertion loss• Amplifier spontaneous emission (ASE)• Chromatic dispersion (CD) or group velocity
dispersion (GVD)• Polarization dispersion mode (PMD)• Polarization dependent losses (PDL)• Crosstalk (XT) (both inter- and intra-channel)• Filter concatenation (FC)
3.7 Non-Linear Impairments
• Self Phase Modulation (SPM)• Cross Phase Modulation (XPM)• Four-wave Mixing (FWM)• Stimulated Brillouin Scattering (SBS)• Stimulated Raman Scattering (SRS)
3.8 Future works